The present invention relates generally to medical treatments. More specifically, the present invention relates to the detection of needle dislodgement during medical treatments or therapies, such as hemodialysis.
A variety of different medical treatments relate to removing blood from a patient. For example, hemodialysis treatment utilizes the patient's blood to remove waste, toxins and excess water from the patient. The patient is connected to a hemodialysis machine, and the patient's blood is pumped through the machine. Waste, toxins and excess water are removed from the patient's blood, and the blood is infused back into the patient. Needles are inserted into the patient's vascular access, such as arteries and veins, to transfer the patient's blood to and from the hemodialysis machine. Hemodialysis treatments can last several hours and are generally performed in a treatment center about three to four times per week.
During hemodialysis treatment, dislodgement of the needle inserted into the patient's vascular access, such as veins, can occur. If not detected immediately, this can produce a significant amount of blood loss to the hemodialysis patient. Two important criteria for detecting needle dislodgement are high sensitivity and specificity of the detection method with respect to needle dropout. This can ensure and facilitate a fast response time in order to minimize blood loss due to dislodgement.
Typically, patients undergoing hemodialysis are visually monitored in order to detect needle dislodgement. However, the needle may not be in plain view of the patient or medical staff such that it could delay responsive actions to dislodgement, such as stopping the blood pump of the hemodialysis machine.
Although devices which employ sensors are available and known for detecting a variety of different bodily fluids, these devices may not be suitably adapted to detect needle dislodgement. For example, known devices employing such sensors have been utilized to detect bedwetting and diaper wetness. However, these types of wetness detection devices may not provide an adequate level of sensitivity if applied to detecting blood loss from the patient due to needle dislodgement.
In this regard, the known wetness detection devices may not be able to detect needle drop out with sufficient enough sensitivity and specificity to ensure and facilitate a proper and fast response. Further, as applied to hemodialysis, known wetness detection devices may not be configured to be controllably interfaced, or at least not properly interfaced, with, for example, a hemodialysis machine such that responsive measure can be taken to minimize blood flow due to needle dislodgement once detected. In addition, a number of known wetness detectors are not reusable, or at least must be cleaned after each use, due to the fact that the sensor component contacts fluid when detecting same. This can require extensive cleaning of the sensor, particularly if it has contacted blood, in order to minimize the risk of infection prior to reuse.
Accordingly, efforts have been directed at designing devices for detecting needle dislodgement wherein detection is sensitive and specific to needle drop out or dislodgement such that responsive measures can be suitably taken to minimize blood loss from the patient due to needle dislodgement.